This invention relates generally to a portable electric humidifier and, more particularly, to a portable electric humidifier having an automatic bacteriastat dispenser.
Many types of humidifiers are used to increase environmental humidity. Such humidifiers use a variety of different output mechanisms to disperse, from a supply reservoir, water which has been preconditioned by, for example, atomization, evaporation or vaporization. Generally the supply reservoir is replenished by a supply tank periodically filled with a convenient source of tap water.
Humidifier operating problems are caused by biological organisms existing in the tap water or acquired from the surrounding air. The warm, moist, oxygen rich environment associated with a humidifier provides an excellent habitat for biological growth which can include algeas, slimes, and bacteria. In addition to being unsightly, such growths can foul humidifier operating surfaces resulting in reduced operating efficiency.
Problems associated with biological growth can be significantly reduced by the addition of suitable biocide chemicals such as a bacteriastat to the water employed in the humidifier. Typically, water treatment substances are added to tap water used to fill a storage tank which provides a controlled flow of water to the humidifier's operating reservoir. However, the addition of water treatment materials during each tank refilling operation is tedious and time consuming. Consequently, water treatment procedures often are ignored resulting in biological growth that decreases operating efficiency.
Disclosed in the prior art are systems for controlling biological growth in portable humidifiers. For example, U.S. Pat. No. 4,663,091 discloses an electrode system for water sterilization; U.S. Pat. No. 5,110,511 discloses a system for timed release of a biocide; and U.S. Pat. No. 5,248,454 discloses a water supply tube coated with an algicide. Also, U.S. Pat. No. 4,701,286 discloses an evaporative cooler having a dispenser. However, none of the prior control systems has been economically and operationally suitable for conventional portable humidifiers.
The object of this invention, therefore, is to provide an improved portable humidifier that alleviates operating problems associated with biological growth.